Osh(1) is an enhanced, backward-compatible port of the Sixth Edition
Thompson shell. Sh6(1) is an unenhanced port of the shell, and
glob(1) is a port of its global command. Together, sh6 and glob
provide a user interface which is backward compatible with that
provided by the Sixth Edition Thompson shell and global command,
but without the obvious enhancements found in osh.

The original Thompson shell was principally written by Ken Thompson
of Bell Labs.
